Siemens Simatic S7-300, Hardware And Installation Manual, Page: 174 / 242

Testing functions, Diagnostics and Fault Elimination
S7-300 Programmable Controller Hardware and Installation
10-14
A5E00105492-01
Event What happens in the DP Slave?
Bus failure interrupt
(short-circuit,
connector unplugged)
•
Call of OB 86 with the message Station failure (coming
event; diagnostic address of the DP slave assigned to the DP
master)
•
with I/O access: Call of OB122 (I/O access error)
DP slave: RUN
→
STOP
•
Call of OB82 with the message Module error
(incoming event; diagnostic address of the DP slave assigned
to the DP master; Variable OB82_MDL_STOP=1)
DP slave: STOP
→
RUN
•
Call of OB82 with the message Module OK
(outgoing event; diagnostic address of the DP-Slave assigned
to the DP master; Variable OB82_MDL_STOP=0)
Evaluation in the user program
The table below shows how you can, for example, evaluate RUN to STOP
transitions of the DP slave in the DP master.
Table 10-9 Evaluating RUN to STOP transitions of the DP slave in the DP master
In the DP Master In the DP Slave (CPU 31x-2DP)
Diagnostic addresses: (Example)
Master diagnostic address =1023
Slave diagnostic address =1022
Diagnostic addresses: (Example)
Slave diagnostic address =422
Master diagnostic address = irrelevant
The CPU calls OB 82 with the following
information:
•
OB 82_MDL_ADDR:=1022
•
OB82_EV_CLASS:=B#16#39 (incoming
event)
•
OB82_MDL_DEFECT: = Module error
Tip: The CPU diagnostic buffer also
contains this information
In the user program you should also include
SFC13 "DPNRM_DG" for reading out DP
slave diagnostic data.
←
CPU: RUN -> STOP
The CPU generates a DP slave diagnostics
message frame
10.6.2 Diagnostics of DP CPUs operating as DP Slave
Reading Slave Diagnostic Data
The slave diagnostic data is compliant with EN 50170, Volume 2, PROFIBUS.
Depending on the DP master, diagnostic data for all DP slaves conforming to
standard can be read with STEP 7 .